arm: xen: implement multicall hypercall support.

As part of this make the usual change to xen_ulong_t in place of unsigned long.
This change has no impact on x86.

The Linux definition of struct multicall_entry.result differs from the Xen
definition, I think for good reasons, and used a long rather than an unsigned
long. Therefore introduce a xen_long_t, which is a long on x86 architectures
and a signed 64-bit integer on ARM.

Use uint32_t nr_calls on x86 for consistency with the ARM definition.

Build tested on amd64 and i386 builds. Runtime tested on ARM.

Signed-off-by: Ian Campbell <[email protected]>
Cc: Stefano Stabellini <[email protected]>
Cc: Konrad Rzeszutek Wilk <[email protected]>
Cc: Boris Ostrovsky <[email protected]>
Signed-off-by: David Vrabel <[email protected]>
7 files changed